This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Despite the near complete suppression of detectable virus in many HIV infected patients undergoing highly active antiretroviral therapy, viremia reemerges rapidly after interruption of treatment. Postintegration latency refers to latently infected resting memory CD4+ T cells containing transcriptionally silent integrated HIV-1 genomes. Postintegration latency contributes to the persistence of the virus under HAART and represents a known barrier to eradication of HIV infection.